Training & Nutrition - Questions about the BMI

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View Full Version : Questions about the BMI


CaseyLS
09-22-04, 02:24 PM
I have looked at a few different BMI's and the only information I have seen them ask for is height and weight. How is it they can say some one is obese or overweight if they only know those two things. (I guess they also ask for age too.) Shouldn't it also ask for your body type. I put in information for Darren Sproles, K-State running back, and his BMI score is 29. Which puts him one point away from being obese. My score is a 25(6'5", 210) Which puts me right at overweight. My point is the test doesn't seem to take into account muscle mass vrs fat mass.

So am I the only person who thinks the BMI is a farce?
Are there better tests to look at?

Mainly I am just looking for opinions and I know my opinion isn't laid out well but please feel free to critique it.


Edit for spelling


Hornbiker
09-22-04, 02:33 PM
You're right, the usual BMI test is a total farce. Puts most athletes in the obese category. I think it was designed for sedentary couch potatoes who won't turn off the tv long enough to take a real test. :)

Some more reliable BMI tests require that you also enter measurements from wrist, forearm, waist, etc. which makes much more sense, and has a more accurate BMI result. But I've heard that skin fold tests are one of the most accurate ways to test BMI, and you can get this done at most gyms.

caloso
09-22-04, 03:00 PM
Seems to me that the BMI is pretty worthless for anybody who's at all athletic. I use a scale that estimates your body-fat percentage. And resting heart rate.


SSP
09-22-04, 06:29 PM
For the vast majority of people, Body Mass Index is a reasonable surrogate for "fatness". However, it does not work as well for very tall people, or highly muscular people. Nor does it take into account the general tendency for BMI to increase with age, or the differences in BMI between men and women.

It's popular mainly because it is easy to calculate, and because it is a meaningful number for most people (i.e., most folks with a BMI of 30 really are "obese").

www.halls.md is one of the best sites on the web for understanding BMI. The site also has some very interesting comparisons based on age and gender, and in-depth analysis of the limitations of BMI.

SSP
09-22-04, 06:35 PM
You're right, the usual BMI test is a total farce. Puts most athletes in the obese category. I think it was designed for sedentary couch potatoes who won't turn off the tv long enough to take a real test. :)

Some more reliable BMI tests require that you also enter measurements from wrist, forearm, waist, etc. which makes much more sense, and has a more accurate BMI result. But I've heard that skin fold tests are one of the most accurate ways to test BMI, and you can get this done at most gyms.

Depends on your definition of "athlete". Most competitive cyclists, runners, and triathletes are well below the "overweight" cutoff of 25.

FWIW, BMI calculations never involve measurements other than height and weight. And skinfold tests do not measure "BMI". Those other tests are ways of estimating "body fat percentage", which is not the same as Body Mass Index (BMI).

For athletes, body fat percentage is a better way of analyzing body composition and weight than BMI. For most non-athletes, BMI is a reasonable, quickly calculated and easily understood alternative.

For anyone who's interested, here's a link to a website that will estimate your body fat percentage, using several simple body circumference measurements. The formula they use was originally developed by the US Navy, and has since been adopted by the Dept. of Defense as their standard way of estimating body fat percentage for all military personnel.

http://www.he.net/%7Ezone/prothd2.html

Guest
09-22-04, 06:35 PM
The more athletically inclined you are, the less that scale (or any other where someone doesn't see you and lay hands on you) is accurate. It's such a joke.

Koffee

CaseyLS
09-23-04, 12:30 PM
The formula that I saw for it yesterday was

(body weight/[height in inches*height in inches])*706

God if I lifted weights at all I would have a good chance at being way over weight.

Hornbiker
09-23-04, 12:58 PM
.
FWIW, BMI calculations never involve measurements other than height and weight. And skinfold tests do not measure "BMI". Those other tests are ways of estimating "body fat percentage", which is not the same as Body Mass Index (BMI).

For athletes, body fat percentage is a better way of analyzing body composition and weight than BMI. For most non-athletes, BMI is a reasonable, quickly calculated and easily understood alternative.


Saw that particular test that included measurenments on a web site some time ago...it must have been a test that combined BMI and body fat percentage. Yes, skin fold is for body fat, not BMI---I mis-spoke (mis-wrote?)

SSP
09-23-04, 01:20 PM
Saw that particular test that included measurenments on a web site some time ago...it must have been a test that combined BMI and body fat percentage. Yes, skin fold is for body fat, not BMI---I mis-spoke (mis-wrote?)

No worries. I have a professional interest in the subject, as BMI and body fat calculations are part of both my CycliStats program ( http://www.CycliStats.com ), and my WeightWare program ( http://www.WeightWare.com ). Confusing BMI and body fat percentage is common, and understandable because they tend to be closely related (with the exception of very tall and very muscular people).

BTW - where in Oregon are you located? My fiance and I have been thinking of moving up to Bend. We visit there once or twice per year, and really enjoy the town...they've done an incredible job with their downtown and waterfront district.

Hornbiker
09-23-04, 02:31 PM
BTW - where in Oregon are you located? My fiance and I have been thinking of moving up to Bend. We visit there once or twice per year, and really enjoy the town...they've done an incredible job with their downtown and waterfront district.

I live in Ashland, about 14 miles from the CA border. Bend and Ashland are easily my favorite places in Oregon...I go to Bend a lot, especially in Winter to ski/snowboard at Mt Bachelor. Ashland's great too---our own mountain, very culturally active in the arts, and the biking possibilities are endless for roadies and MTB (as in Bend). Stinkin' expensive to buy a home, but still worth it IMO!

SSP
09-23-04, 02:57 PM
I live in Ashland, about 14 miles from the CA border. Bend and Ashland are easily my favorite places in Oregon...I go to Bend a lot, especially in Winter to ski/snowboard at Mt Bachelor. Ashland's great too---our own mountain, very culturally active in the arts, and the biking possibilities are endless for roadies and MTB (as in Bend). Stinkin' expensive to buy a home, but still worth it IMO!

Cool...did you ride the Siskiyou Century on Sept. 11th? It was about halfway between Redding and Ashland, so perhaps we've met.

I normally ski at Mt. Shasta (and Mt. Bachelor) but I've been meaning to check out Ashland's hill for a while now.

Hornbiker
09-23-04, 03:40 PM
Cool...did you ride the Siskiyou Century on Sept. 11th? It was about halfway between Redding and Ashland, so perhaps we've met.

I normally ski at Mt. Shasta (and Mt. Bachelor) but I've been meaning to check out Ashland's hill for a while now.

In fact I did ride the Siskiyou, but only did the metric w/some friends. Very flat and very fast! :)

Did you do the Mt Shasta Century? NOT flat, and NOT fast!

Mt. Shasta's where I learned to snowboard. Much friendlier "newbie" terrain there. Mt Ashland is not for the faint of heart, but it's a kick for such a small ski area. A lot of off piste opportunities if you like that kind of thing, and they don't groom the heck out of every run. Almost no beginning/intermediate runs, although they are planning a highly controversial expansion.

SSP
09-23-04, 03:56 PM
In fact I did ride the Siskiyou, but only did the metric w/some friends. Very flat and very fast! :)

Did you do the Mt Shasta Century? NOT flat, and NOT fast!

Mt. Shasta's where I learned to snowboard. Much friendlier "newbie" terrain there. Mt Ashland is not for the faint of heart, but it's a kick for such a small ski area. A lot of off piste opportunities if you like that kind of thing, and they don't groom the heck out of every run. Almost no beginning/intermediate runs, although they are planning a highly controversial expansion.

I rode the Siskiyou Century (105 miles, with 5300 feet of climbing) for the first time in several years (since they changed the course to run counter-clockwise). Got in with a good strong group early and hung in all day, finishing with an average speed of 18.827 mph - I think it was my fastest century ever. :D

I've not done the Mt. Shasta Century, but have been meaning to check it out. I might try and tackle the Super Century next year, if I can find time to train for it.

Sounds like I will have to get up to Ashland this winter...I ski and enjoy tackling the ungroomed stuff if the snow is light enough.

fatbottomgirl
09-25-04, 11:01 AM
I believe BMI was developed as a way for doctors and nurses to calculate medicine dosages. Fat or muscle, its a useful way to know how much blood you have flowing in you. We use it all the time in the hospital. I have a BMI of 25 too, 5' 2" 140lbs, but I have a resting heart rate of 60, good bp, and can take the steepest hills in Seattle whistling dixie, so what do I care? I think waist circumfrance, heart rate, blood pressure and HOW YOU FEEL are more important than a silly number. Use that to train with!

Guest
09-25-04, 11:43 AM
I believe BMI was developed as a way for doctors and nurses to calculate medicine dosages. Fat or muscle, its a useful way to know how much blood you have flowing in you. We use it all the time in the hospital. I have a BMI of 25 too, 5' 2" 140lbs, but I have a resting heart rate of 60, good bp, and can take the steepest hills in Seattle whistling dixie, so what do I care? I think waist circumfrance, heart rate, blood pressure and HOW YOU FEEL are more important than a silly number. Use that to train with!


I feel the same way- I could care less about the BMI, except that the insurance company ruled me out for the highest benefit insurance package based on my BMI being too high. My BMI puts me at one bodyfat percentage, but my skinfold test has me at a significantly lower bodyfat. I gave them my bodyfat analysis and mentioned all the weightlifting I did, but of course, that didn't get taken into account at all. So I'm stuck paying a lot more for my insurance. I will probably appeal, though. I'll submit my fitness assement showing my fitness.

I find it absolutely amazing that an insurance company can go by a BMI test and someone who can be up to 30% fat with very little muscle can be seen as "fit" and receive the full benefits, whereas someone who is very muscular and has very little fat would weigh more and be classified as "fat" and get denied certain benefits. :rolleyes:

Koffee

MsMittens
09-25-04, 11:57 AM
For anyone who's interested, here's a link to a website that will estimate your body fat percentage, using several simple body circumference measurements. The formula they use was originally developed by the US Navy, and has since been adopted by the Dept. of Defense as their standard way of estimating body fat percentage for all military personnel.

http://www.he.net/%7Ezone/prothd2.html


Just for giggles I decided to give it a shot (I did notice that this seems to be tied with the "Zone" Diet but didn't pull up a meal plan when I requested it -- the main site is http://www.he.net/~zone/) but I used my figures from Last April/03 versus present measurements:

April/03:

Hgt: 61 inches
Wgt: 210lbs
BFI: 52%
Lean Mass: 101lbs
"Ideal" Weight: 123

Versus

Sept 25/2004

Hgt: 61 inches (I need one of those torture racks to change this) ;)
Wgt: 170lbs
BFI: 34%
Lean Mass: 114 lbs
"Ideal" Weight: 137lbs.

I find it interesting that the ideal weight has changed. I mean, personally my goal has been to hit somewhere around 135-140 although I'm very pleased with where I'm at. Compared to others I know who are skinner than me, I have better endurance plus have tonnes of fun when cycling (like I'd be able to see a wolf when in a car!? -- Sheesh).

I've been a bit slacking on my weightlifting over the summer (enjoying as much outdoors as I can) but I suspect once I get back into that, the LM will pick up. That all said, one thing I did decide for myself when first looking into seriously dealing with my weight issue was that a) I was going to have fun b) I wasn't interested in starving or depriving myself because I knew that'd be my downfall. I've succeeded thus far, have maintained with minimal gains (I tend to gain at Christmas just because there is sooooooooo much good food to sample.. ;) ).

SSP
09-25-04, 12:10 PM
I feel the same way- I could care less about the BMI, except that the insurance company ruled me out for the highest benefit insurance package based on my BMI being too high. My BMI puts me at one bodyfat percentage, but my skinfold test has me at a significantly lower bodyfat. I gave them my bodyfat analysis and mentioned all the weightlifting I did, but of course, that didn't get taken into account at all. So I'm stuck paying a lot more for my insurance. I will probably appeal, though. I'll submit my fitness assement showing my fitness.

I find it absolutely amazing that an insurance company can go by a BMI test and someone who can be up to 30% fat with very little muscle can be seen as "fit" and receive the full benefits, whereas someone who is very muscular and has very little fat would weigh more and be classified as "fat" and get denied certain benefits. :rolleyes:

Koffee

Just for clarification, your BMI did not "put you at one bodyfat percentage". BMI is only a way of comparing your weight to your height, and says nothing about body composition.

High BMI's have been associated with increased mortality in many large-scale studies, so the insurance company's response is predictable, if not fair. Insurance companies are just sophisticated gamblers. If you're insuring hundreds of thousands of people, and know that (on average) the folks with high BMI's will die sooner and/or have increased health costs, then it makes sense from their perspective for those rates to be higher.

Is that fair? Hard to say. I have to pay higher rates because my Dad died from a heart attack at age 47...but, he was an overweight smoker, while I'm a thin hard-core cyclist. From the insurance company's perspective, my Dad's death is a "risk factor" and they have data on their side to back that up.

Fortunately, recent research shows that fitness is at least as important as "fatness" or high BMI's (at least for men). Hopefully, this research will result in the insurance companies offering some sort of appeals process (e.g., a treadmill stress test), to allow for fit, but heavy, folks to show that they qualify for reduced rates.

Good luck with your appeal...let us know how it comes out.

SSP
09-25-04, 12:29 PM
Just for giggles I decided to give it a shot (I did notice that this seems to be tied with the "Zone" Diet but didn't pull up a meal plan when I requested it -- the main site is http://www.he.net/~zone/) but I used my figures from Last April/03 versus present measurements:

April/03:

Hgt: 61 inches
Wgt: 210lbs
BFI: 52%
Lean Mass: 101lbs
"Ideal" Weight: 123

Versus

Sept 25/2004

Hgt: 61 inches (I need one of those torture racks to change this) ;)
Wgt: 170lbs
BFI: 34%
Lean Mass: 114 lbs
"Ideal" Weight: 137lbs.



That is outstanding progress, MM!! Your rate of weight loss is very reasonable and healthy, and the fact that you've incorporated physical activity is excellent. It's amazing what small changes, applied over time, can accomplish. According to my calculations, you have averaged a deficit of 270 calories per day for the last 17 months, which is a very good thing.

Have you ever heard of the National Weight Control Registry (http://www.nwcr.ws/)? It's an academic research project that is studying how successful weight loss happens. I'm pretty sure you meet their research criteria, so you may want to visit that site and submit your results. Successful, long-term weight loss is fairly rare, so hopefully your story will help them to understand the strategies that are common to "successful losers".

MsMittens
09-25-04, 12:32 PM
Have you ever heard of the National Weight Control Registry? It's an academic research project that is studying how successful weight loss happens. I'm pretty sure you meet their research criteria, so you may want to visit that site and submit your results. Successful, long-term weight loss is fairly rare, so hopefully your story will help them to understand the strategies that are common to "successful losers".

Actually yes, although being a Canadian might preclude me from being part of that study. I was first introduced to the NWCR through the book Thin for Life, which isn't a diet book persay but rather looks at the perceptions on dieting and how people maintain their weight (even if it's not the "ideal" weight) for extended periods. It's part of what helped me change my views on weight loss (I had tried a variety of things including Body for Life).

BTW, I do love the CycliStats software. ;)

Guest
09-25-04, 12:42 PM
Just for clarification, your BMI did not "put you at one bodyfat percentage". BMI is only a way of comparing your weight to your height, and says nothing about body composition.

High BMI's have been associated with increased mortality in many large-scale studies, so the insurance company's response is predictable, if not fair. Insurance companies are just sophisticated gamblers. If you're insuring hundreds of thousands of people, and know that (on average) the folks with high BMI's will die sooner and/or have increased health costs, then it makes sense from their perspective for those rates to be higher.

Is that fair? Hard to say. I have to pay higher rates because my Dad died from a heart attack at age 47...but, he was an overweight smoker, while I'm a thin hard-core cyclist. From the insurance company's perspective, my Dad's death is a "risk factor" and they have data on their side to back that up.

Fortunately, recent research shows that fitness is at least as important as "fatness" or high BMI's (at least for men). Hopefully, this research will result in the insurance companies offering some sort of appeals process (e.g., a treadmill stress test), to allow for fit, but heavy, folks to show that they qualify for reduced rates.

Good luck with your appeal...let us know how it comes out.

The BMI puts me at a higher bodyfat percentage if it says I'm obese. Which it does. And anyone looking at me can see that clearly, I am not. However, I do lift VERY heavy weights, and I do know I am overfat, but not as much as that scale insinuates.

I could see someone arguing that the BMI is more accurate for those who do very little for exercise. HOWEVER, as I said before, the fitter you are, the more you weightlift, the less likely it's going to be accurate. Muscle weighs more than fat, and there's absolutely no wiggle room or acknowledgement by the BMI to account for this. Even ACSM said as much, but of course, they don't recommend anything in place of the BMI either. That doesn't make the insurance companies sophisticated gamblers... it makes them cheap bastards who are too lazy and/or innovative to take into consideration the people who fall outside the usual standards they use for the lazy couch potato bastards who eat their chips and laze in bed all day.

Insurance companies wildly wave their charts and data at us and claim that they've got all this evidence to support their claims. I seriously doubt those charts and data they throw out are reliable, since I think they get the most biased information they can possibly get so they can force most people to pay the most amount of money to them. If they really are interested in seeing how healthy a person is, they would subject them to a stress test, a bodyfat percentage measurement, and a VO2 max test. A lactate test would be nice too. Taking blood is well and good, but if they don't take into account true fitness, then I just think it's a joke and a waste of time.

I saw an attorney to see how far I could pursue this in the event my appeal doesn't work out for me. So we'll see what happens.

Koffee

SSP
09-25-04, 12:46 PM
Actually yes, although being a Canadian might preclude me from being part of that study. I was first introduced to the NWCR through the book Thin for Life, which isn't a diet book persay but rather looks at the perceptions on dieting and how people maintain their weight (even if it's not the "ideal" weight) for extended periods. It's part of what helped me change my views on weight loss (I had tried a variety of things including Body for Life).

BTW, I do love the CycliStats software. ;)

Thanks! You might also be interested in my WeightWare program ( http://www.WeightWare.com ). It's a weight and health diary that uses the same database as CycliStats (so, if you've been entering your weight in CycliStats already, all that data will be in WeightWare when you first start the program).

BTW - The NWCR does not require that you be a citizen of the USA to be included as a participant in their studies.

SSP
09-25-04, 01:01 PM
Insurance companies wildly wave their charts and data at us and claim that they've got all this evidence to support their claims. I seriously doubt those charts and data they throw out are reliable, since I think they get the most biased information they can possibly get so they can force most people to pay the most amount of money to them. If they really are interested in seeing how healthy a person is, they would subject them to a stress test, a bodyfat percentage measurement, and a VO2 max test. A lactate test would be nice too. Taking blood is well and good, but if they don't take into account true fitness, then I just think it's a joke and a waste of time.


Typically, the insurance companies just use published scientific research, and incorporate it into their rate tables. For example, a very large-scale BMI study (with over 1 million subjects), published in the New England Journal of Medicine (http://content.nejm.org/cgi/content/full/341/15/1097) found that: "The risk of death from all causes, cardiovascular disease, cancer, or other diseases increases throughout the range of moderate and severe overweight for both men and women in all age groups.". Based on their analysis of mortality rates, they found that, the lowest rates of mortality were associated with BMI's of 23.5 to 24.9 for men and 22.0 to 23.4 for women. Interestingly, they also found that "the risk associated with a high body-mass index is greater for whites than for blacks".

As for insurance companies offering "stress test, a bodyfat percentage measurement, and a VO2 max test"...don't hold your breath. Testing all applicants like this would be: a) very expensive, and b) risk lawsuits due to some folks dropping dead during the testing procedures :eek:.

fatbottomgirl
09-25-04, 02:47 PM
I'm sorry that insurance is so narrow minded. All the more reason that its important that we shouldn't be, especially about ourselves. Obese people die younger for a lot of different reasons, not just fat. They tend to eat a lot of sugar ( diabetes), industrial pastries and fast food (trans fatty acids and cholestorol) and don't move much (heart disease). My point is that while too much fat IS bad, its not the fat alone that is bad, its the fat lifestyle. We are nutso about body figure in our culture, when the truth is that health is what we should worry about, and thats harder to define than a number. If I tell you one person has a BMI of 40 and one of 22, which is healthier? What if I told you person two is undergoing extensive chemotherapy? Or they smoke a pack a day?

SSP
09-25-04, 03:08 PM
I'm sorry that insurance is so narrow minded. All the more reason that its important that we shouldn't be, especially about ourselves. Obese people die younger for a lot of different reasons, not just fat. They tend to eat a lot of sugar ( diabetes), industrial pastries and fast food (trans fatty acids and cholestorol) and don't move much (heart disease). My point is that while too much fat IS bad, its not the fat alone that is bad, its the fat lifestyle. We are nutso about body figure in our culture, when the truth is that health is what we should worry about, and thats harder to define than a number. If I tell you one person has a BMI of 40 and one of 22, which is healthier? What if I told you person two is undergoing extensive chemotherapy? Or they smoke a pack a day?

Good points. There is certainly more to health and fitness than BMI...it's just part of the overall picture.

As for "its not the fat alone that is bad"...some recent research is clarifying this a bit.

In two different studies on women, they found that "fit but fat" women had a much lower incidence of heart disease...to the extent that it appears it is better to be "fit but fat", rather than "thin, but not fit". However, a second study showed that the risk for women of developing diabetes increases with "fatness", regardless of how fit you are.

For men, a recent study published in the American Journal of Clinical Nutrition (http://www.ajcn.org/cgi/content/full/69/3/373) concluded, "The health benefits of leanness are limited to fit men, and being fit may reduce the hazards of obesity." This was true for all causes of mortality.

Hopefully, as more of this research gets published, the insurance companies will figure out some way to incorporate it into their rates, so that fit people are appropriately rewarded for their healthy lifestyle choices.

CdCf
09-25-04, 06:52 PM
BMI is very useful as a tool to judge the fitness level of a large group of people.

We have conscription here in Sweden, so all male citizens over 18 have to go through a series of tests. Mental, physical and medical.
The height and weight data is entered into a database and comparisons can be made with previous years' "recruits".

Here, BMI is excellent. It accurately shows that we're now slightly taller than 25 years ago, but much fatter (up by 3-4 kg (7-9 lbs)). One of the tests is a constant-load strength test, so the average weight gain can be ruled out as being an increase in muscle mass.

On an individual level, BMI is almost useless.
A thin person can actually have a body fat percentage that is too HIGH, but still have a BMI that is within the normal range, and even a bit too low.
They look thin because they have very little muscle mass, but the amount of fat they carry could well have the same mass as a much larger, normal, person.

Conversely, a very muscular person, with very little body fat, will likely get an "obese" BMI value.

Fat percentage is a much better indicator for health level.

My BMI is 24, but I'm about 12-15 lbs overweight.

bbp
09-26-04, 12:31 AM
Just measure your BF%

MsMittens
09-26-04, 04:18 AM
Just measure your BF%


Uh... how?

bbp
09-26-04, 08:47 AM
http://www.he.net/~zone/prothd2.html

you can measure it yourself or you can use one of those electronic bf calculators. They aren't really accurate but it should be able to tell you if youre losing or gaining fat over time.

TomM
09-26-04, 01:20 PM
BMI is only a way of comparing your weight to your height, and says nothing about body composition.


If that's all it does, why don't they just divide weight by height? Sure would simplify the math.

Guest
09-27-04, 09:39 PM
It still leaves the same problem.

I have a friend that lives in Australia that rows professionally. When I first met him I was shocked. He stood up, and he looked like a tree- seriously. At 6 foot 8, I estimate he was easily 240, due to the incredible muscle mass he had. He used to make a muscle with his biceps for me, and I swear he looked like Popeye the sailor man *toot toot!*. Someone like him would not work for BMI, but I've seen him up close and personal- not an ounce of bodyfat on him anyplace.

Damn, he was fine, though... :p

Koffee

joejack951
09-27-04, 09:59 PM
SSP,

Thanks for the BF calculator link. I've been quite curious lately as to my body fat percentage. My BMI is a little over 25 telling me that I need to lose 5 more pounds to be borderline normal weight. Seeing as how I've recently lost 25 lbs. and feel as though I'm now in great shape, I found this ridiculous. Based on that calculator you provided, it is:

Your Recommended Blocks
Your weight is: 173 pounds
Your sex is: Male
Your Body Fat percentage is: 13
Your Lean Body Mass is: 151 pounds
Your 'Ideal' weight is: 173 pounds
Your activity factor is: 0.87
Your recommend blocks per day are: 18 (135 grams of protein)

My weight lately has hovered between 170 and 175 so I picked the halfway point. Seeing as how this calculator shows me to be right where I should be and the last time I was in as good of shape as I am now I also weighed around 170 lbs., I'm thinking this one is pretty accurate.

Guest
09-27-04, 10:11 PM
Ummmm... 13 percent is overweight? In whose reality? Boy, you are skin in bones in my book!

There has to be some fat there at the very least for fat soluble vitamins to absorb in your body for nutritional purposes!

If you feel like you're in your prime, it's just another reason to ignore the BMI.

Koffee

caloso
09-28-04, 09:27 AM
JoeJack, I think you've perfectly demonstrated the problem with the BMI.

SSP
09-28-04, 10:13 AM
SSP,

Thanks for the BF calculator link. I've been quite curious lately as to my body fat percentage. My BMI is a little over 25 telling me that I need to lose 5 more pounds to be borderline normal weight. Seeing as how I've recently lost 25 lbs. and feel as though I'm now in great shape, I found this ridiculous. Based on that calculator you provided, it is:

Your Recommended Blocks
Your weight is: 173 pounds
Your sex is: Male
Your Body Fat percentage is: 13
Your Lean Body Mass is: 151 pounds
Your 'Ideal' weight is: 173 pounds
Your activity factor is: 0.87
Your recommend blocks per day are: 18 (135 grams of protein)

My weight lately has hovered between 170 and 175 so I picked the halfway point. Seeing as how this calculator shows me to be right where I should be and the last time I was in as good of shape as I am now I also weighed around 170 lbs., I'm thinking this one is pretty accurate.

How tall are you?

FYI - your body fat percentage (13%) falls between the American Dietetic Association's recommendations for "Healthy Males" (15-18%), and "Athletic Males" (5-12%).

joejack951
09-28-04, 10:20 AM
I'm 5' 8.5". I could probably drop another 5 pounds by eating a little less and be considered "athletic" although if you take my morning weight, which is 170, then I'm already there :)

Funny how ADA says I'm athletic and BMI says I'm overweight.

SSP
09-28-04, 11:02 AM
I'm 5' 8.5". I could probably drop another 5 pounds by eating a little less and be considered "athletic" although if you take my morning weight, which is 170, then I'm already there :)

Funny how ADA says I'm athletic and BMI says I'm overweight.

Yeah...BMI does have limitations when applied to individuals. On the other hand, that web site's body fat estimator also has limitations - even when the measurements are taken accurately, it's only estimated to be within +/- 3%. In particular, the measurement is very sensitive to the abdominal circumference measurement. The Navy protocol states that the measurement be taken by a trained technician. They take it just below the navel, after a relaxed exhalation of breath, and they take care to not "tighten" the tape, and keep it level. They also take three measurements, and plug in the average of the three.

Of course, the real "results" of exercise and diet are how you feel, how you think you look in the mirror, and how fast you are on the bike. :D

One other question...how old are you? One of the limitations of BMI is that it tends to change with age, but the cutoffs for overweight/obese don't take this into account. On Dr. Steven Halls website ( http://www.halls.md ) he discusses this issue, and he has come up with his own formula for taking age into account when characterizing BMI. His site can also tell you your "weight percentile" (compared to US averages for your gender, age, height, and weight). His BMI calculator is here: http://www.halls.md/body-mass-index/av.htm

joejack951
09-28-04, 12:53 PM
Yeah...BMI does have limitations when applied to individuals. On the other hand, that web site's body fat estimator also has limitations - even when the measurements are taken accurately, it's only estimated to be within +/- 3%. In particular, the measurement is very sensitive to the abdominal circumference measurement. The Navy protocol states that the measurement be taken by a trained technician. They take it just below the navel, after a relaxed exhalation of breath, and they take care to not "tighten" the tape, and keep it level. They also take three measurements, and plug in the average of the three.

Of course, the real "results" of exercise and diet are how you feel, how you think you look in the mirror, and how fast you are on the bike. :D

One other question...how old are you? One of the limitations of BMI is that it tends to change with age, but the cutoffs for overweight/obese don't take this into account. On Dr. Steven Halls website ( http://www.halls.md ) he discusses this issue, and he has come up with his own formula for taking age into account when characterizing BMI. His site can also tell you your "weight percentile" (compared to US averages for your gender, age, height, and weight). His BMI calculator is here: http://www.halls.md/body-mass-index/av.htm

I'm by no means trained in taking measurements, and for all I know, mine might have been off by a bit (although I've measured my waist several times and it's always been 31 inches). I'm 25 years old (26 in a few months) so you'd think the standard BMI calculation would apply to me.

Even on that website, I'm considered "marginally overweight" and in the 60% (of whoever was measured for that statistic). I've always weighed more than people my height but I've also always been stronger and in better shape than them. But, in the end, I'm quite happy with how I look and the only reason I have for wanting to drop a few more pounds is to be faster on hills.

collegeskier
09-28-04, 04:13 PM
From everything I have read being tall causes huge problems for anything over like 6 feet and the number just don't make sense. The orginal poster said he was 6'8" I believe so I for you BMI is a farse. And instead of remember the english formula it is just your weight in kilograms divided by your height in meters squared (square height before dividing). One more reason to go metric.